Secondary Sources-AG

http://www.encyclopedia.com/topic/Internal_Migration.aspx#1-1G2:3401802654-full - reasons for internal migration
http://www.encyclopedia.com/doc/1G2-3401804525.html- western migration
http://memory.loc.gov/ammem/cbhtml/cbturn.html - post gold rush troubles for the west coast
http://memory.loc.gov/ammem/cbhtml/cbrush.html - after the gold rush settlement (includes farming, land, laws, and transportation from the east)
http://memory.loc.gov/ammem/cbhtml/cbmagnet.html - tourism and real-estate in the west coast
http://www.nationsencyclopedia.com/economies/Americas/United-States-of-America.html -America location and size